Columbia Encyclopedia

Search results

500 results found

Brownian movement

(Encyclopedia)Brownian movement or motion, zigzag, irregular motion exhibited by minute particles of matter when suspended in a fluid. The effect has been observed in all types of colloidal suspensions (see colloid...

LSD

(Encyclopedia)LSD or lysergic acid diethylamide līˌsûrˈjĭk, dīˌĕthˈələmĭd, dīˌĕthəlămˈĭd [key], alkaloid synthesized from lysergic acid, which is found in the fungus ergot (Claviceps purpurea). I...

gonadotropic hormone

(Encyclopedia)gonadotropic hormone gōˌnădətrŏpˈĭk [key] or gonadotropin, any one of three glycoprotein (see protein) hormones released by either the anterior pituitary gland or the placenta (the organ in whi...

bass, in zoology

(Encyclopedia)bass băs [key], common name applied to various fishes of Centrarchidae (black basses and sunfishes), Serranidae (sea basses and groupers), Moronidae (temperate basses), and other families. All basses...

life

(Encyclopedia)life, although there is no universal agreement as to a definition of life, its biological manifestations are generally considered to be organization, metabolism, growth, irritability, adaptation, and ...

infancy

(Encyclopedia)infancy, stage of human development lasting from birth to approximately two years of age. The hallmarks of infancy are physical growth, motor development, vocal development, and cognitive and social d...

temperature

(Encyclopedia)CE5 Temperature scales temperature, measure of the relative warmth or coolness of an object. Temperature is measured by means of a thermometer or other instrument having a scale calibrated in unit...

diffusion

(Encyclopedia)diffusion, in chemistry, the spontaneous migration of substances from regions where their concentration is high to regions where their concentration is low. Diffusion is important in many life process...

avalanche

(Encyclopedia)avalanche, rapidly descending large mass of snow, ice, soil, rock, or mixtures of these materials, sliding or falling in response to the force of gravity. Avalanches, which are natural forms of erosio...

Robinson, Sugar Ray

(Encyclopedia)Robinson, Sugar Ray, 1920–89, American boxer, b. Detroit as Walker Smith, Jr. He began boxing after three years of high school in New York City. Having won all his amateur fights (about 90), includi...